Distillation device

ABSTRACT

The present application relates to a distillation device, and according to the distillation device of the present application, in first and second compounds being capable of forming an azeotrope, by introducing the second compound having a relatively high boiling point into a supply port located below the first compound having a relatively low boiling point, the first compound can be previously separated from the top of a first distillation column and the content of the first compound in the flow discharged from the bottom of the first distillation column can be minimized, and thus, as a moving route of the first compound is minimized, the second compound can be separated in high purity.

The present application is a National Stage Application No.PCT/KR2016/007021, filed Jun. 30, 2016, and claims the benefit ofpriority based on Korean Patent Application No. 10-2015-0093695 datedJun. 30, 2015, all of which are hereby incorporated by reference intheir entirety for all purposes as if fully set forth herein.

TECHNICAL FIELD

The present application relates to a distillation device.

BACKGROUND ART

Phenol is used in various fields as feedstocks of various syntheticresins such as polycarbonate resin and epoxy resin, including phenolresin, or feedstocks in the pharmaceutical industry, and feedstocks ofdetergents, such as nonylphenol, or various color paints.

Methods for producing phenol from cumene are well known. For example,the cumene is oxidized using a gas containing oxygen to form cumenehydroperoxide, which is again decomposed under an acidic catalyst,thereby resulting in phenol and acetone.

In the process of generating phenol as above, various side reactionsoccur at the same time. For example, dimethylbenzyl alcohol (DMBA) isformed as a major by-product in the oxidation step and is dehydratedsubsequently in the same acid catalytic cracking step to producealpha-methylstyrene (AMS). Meanwhile, hydroxyacetone (HA) among the sidereaction products affect most highly on purity of phenol.

Accordingly, a distillation method for separating the hydroxyacetonemore effectively is required.

DISCLOSURE Technical Problem

The present application is intended to provide a distillation devicewhich separates hydroxyacetone and phenol at low cost and high purity.

Technical Solution

One embodiment of the present application provides a distillationdevice. According to the exemplary distillation device of the presentapplication, in a first compound and a second compound being capable offorming an azeotrope, by introducing the second compound having arelatively high boiling point into a supply port located below the firstcompound having a relatively low boiling point, the first compound canbe previously separated from the top of a first distillation column andthe content of the first compound in a flow discharged from the bottomof the first distillation column can be minimized, and thus as themoving route of the first compound is minimized, the second compound canbe separated in high purity. In addition, since the used amount of asolvent, for example water, required for removing the first compound andimpurities can be reduced in the upper portion of a third distillationcolumn, which is a low boiling point component removal device, theenergy saving effect can be maximized

Hereinafter, the distillation device of the present application will bedescribed with reference to the attached drawings, but the attacheddrawings are illustrative, and the distillation device of the presentapplication is not limited by the attached drawings.

FIG. 1 is a diagram schematically showing a distillation deviceaccording to one embodiment of the present application.

As in FIG. 1, the distillation device of the present applicationcomprises at least one or more distillation units. The term“distillation unit” above means one unit body which comprises adistillation column and a condenser and a reboiler, connected to thedistillation column, respectively, and can perform distillationprocesses.

The distillation column is a device being capable of separatingmulti-component materials contained in feedstocks by each boiling pointdifference. Distillation columns having various shapes can be used inthe distillation device of the present application in consideration ofboiling points of components of the introduced feedstocks or componentsto be separated. The specific type of the distillation column which canbe used in the distillation device of the present application is notparticularly limited, and for example, a distillation column having ageneral structure as shown in FIG. 1 or a dividing wall distillationcolumn equipped with a dividing wall inside may be also used. In oneexample, the distillation column can be divided into an upper region anda lower region. The term “upper region” herein may mean a relativelyupper portion in the structure of the distillation column, and forexample, mean the uppermost portion of the divided two regions when thedistillation column is divided into two portions in the height directionor the longitudinal direction of the distillation column In addition,the above “lower region” may mean a relatively lower portion in thedistillation column structure, and for example, mean the downmostportion of the divided two regions when the distillation column isdivided into two portions in the height direction or the longitudinaldirection of the distillation column. Herein, the upper region and thelower region of the distillation column can be used in a relativeconcept to each other. The top of the distillation column is included inthe upper region and the bottom of the distillation column is includedin the lower region; however, unless otherwise defined herein, the upperregion is used in the same sense as the top region and the lower regionis used in the same sense as the bottom region. As the distillationcolumn, a distillation column having a number of theoretical stages of32 to 98 can be used. In the above, the “number of theoretical stages”means a number of imaginary regions or stages in which two phases suchas a vapor phase and a liquid phase in the distillation column are inequilibrium with each other.

In one embodiment, as in FIG. 1, the first distillation unit (10)comprises a first distillation column (100), and a first condenser (110)and a first reboiler (120), connected to the first distillation column(100), respectively. For example, the first distillation column (100),the first condenser (110), and the first reboiler (120) may befluidically connected to each other so that the fluid introduced intothe first distillation column (100) can flow. The “condenser” above is adevice separately installed outside the distillation column, and means adevice for cooling the flow discharged from the top of the distillationcolumn by a method such as contacting it with cooling water introducedoutside. For example, the first condenser (110) of the firstdistillation column (100) is a device for condensing a first top flow(F_(top1)) discharged from the top region of the first distillationcolumn (100), and a second condenser (210) and a third condenser (310)of a second distillation column (200) and a third distillation column(300), which are described below, may be devices for condensing a secondtop flow (F_(top2)) discharged from the top region of the seconddistillation column (200) and a third top flow (F_(top3)) dischargedfrom the top region of the third distillation column (300). In addition,the reboiler” above may be a heating device separately installed outsidethe distillation column and mean a device for again heating andevaporating a flow of high-boiling components discharged from the bottomof the distillation column. For example, the first reboiler (120) of thefirst distillation column (100) is a device for heating a first bottomflow (F_(btm1)) discharged from the bottom region of the firstdistillation column (100), and a second reboiler (220) of the seconddistillation column and a third reboiler (320) of the third distillationcolumn (300), which are described below, may be devices for heating asecond bottom flow (F_(btm2)) discharged from the bottom region of thesecond distillation column (200) and a third bottom flow discharged fromthe bottom region of the distillation column (300).

The first distillation column (100) comprises a first supply port (101)and a second supply port (102) located below the first supply port(101). In one embodiment, when the first distillation column (100) isdivided into an upper region and a lower region, the first supply port(101) may be located at the upper region of the first distillationcolumn (100), and the second supply port (102) may be located at thelower region of the first distillation column (100). In anotherembodiment, both the first supply port (101) and the second supply port(102) may be located at the upper region of the first distillationcolumn (100), where the first supply port (101) may be located above thesecond supply port (102), for example, at the upper stage. In oneexample, the first supply port (101) may be located at 1 to 40% of thenumber of theoretical stages calculated based on the top. In addition,the second supply port (102) may be located at 40 to 100% of the numberof theoretical stages calculated based on the top. For example, when thenumber of theoretical stages of the distillation column is 100 stages,the first stage of the distillation column corresponds to the top andthe 100th stage corresponds to the bottom, where the first supply port(101) can be located at the 1st to 40th stages and the second supplyport (102) can be located at the 40th to 100th stages.

As shown in FIG. 1, the feedstock (F₁) containing the first compoundflows into the first supply port (101) of the first distillation column(100), and the feedstock (F₂) containing the second compound forming anazeotrope with the first compound flows into the second supply port(102).

The first compound and the second compound are not particularly limitedas long as they are mixed with each other to form an azeotrope. The term“azeotrope” above means a liquid mixture in a solution state in whichazeotropy or the like may occur. Generally, if a solution is distilled,the composition changes according to boiling, with usually raising orlowering the boiling point as well, but a certain type liquid having aspecial ratio of components boils without changing the ratio ofcomponents at a certain temperature like a pure liquid, where the ratiosof components in solution and vapor become same, and then the system isreferred to as being in an azeotropic state, the ratio of components isreferred to as an azeotropic composition, the solution is referred to asan azeotrope and the boiling point of the azeotrope is referred to as anazeotropic point. In one example, the first compound may behydroxyacetone, and the second compound being capable of forming anazeotrope with the hydroxyacetone may be alpha-methylstyrene, withoutbeing particularly limited thereto.

In the distillation device of the present application, the first andsecond compounds being capable of forming an azeotrope with each otherare introduced at different positions of the distillation column, and inparticular, the second compound having a relatively high boiling pointof the first and second compounds being capable of forming the azeotropeis introduced into the supply port located below the first compoundhaving a relatively low boiling point, and thus the first compound maybe previously separated from the top of the first distillation column(100) and the content of the first compound in the flow discharged fromthe bottom of the distillation column (100) may be minimized, wherebythe content of the first compound separated from the second distillationcolumn (200) and the third distillation column (300), which aredescribed below, may be minimized That is, according to the distillationdevice of the present application, as the moving route of the firstcompound is minimized, the second compound can be separated to highpurity and the energy saving effect can be maximized.

In one example, the feedstocks (F₁, F₂) containing the first and secondcompounds introduced into the first supply port and the second supplyport (102) of the first distillation column (100), respectively, aredivided to the first top flow (F_(top1)) discharged from the top regionof the first distillation column (100) and the first bottom flow(F_(btm1)) discharged from the bottom region of the first distillationcolumn (100), respectively, and discharged. The first top flow(F_(top1)) discharged from the top region of the first distillationcolumn (100) flows into the first condenser (110) and some or all of thefirst top flow (F_(top1)) passing through the first condenser (110) maybe refluxed to the top region of the first distillation column (100) orstored as a product. In one example, the flow discharged from the firstcondenser (110) flows into a storage tank and is stored, and then can berefluxed to the first distillation column (100) or stored as a product.In addition, a portion of the first bottom flow (F_(btm1)) dischargedfrom the bottom region of the first distillation column (100) may flowinto the first reboiler (120), a portion of the first bottom flow(F_(btm1)) passing through the first reboiler (120) may be refluxed tothe bottom region of the first distillation column (100) and theremaining portion may flow into the second distillation column to bedescribed below.

In one embodiment, the first top flow (F_(top1)) comprises a relativelylow boiling point component of feedstock (F₁, F₂) components introducedinto the first distillation column (100), and in one example, itcomprises the first compound, the second compound, and a substancehaving a boiling point lower than that of the second compound. Inaddition, the first bottom flow (F_(btm1)) comprises a relatively highboiling point component among the components contained in the feedstocks(F₁, F₂) introduced into the first distillation column (100) and in oneexample, it comprises the first compound and a substance having aboiling point higher than that of the first compound. In one example, asdescribed above, the first compound may be hydroxyacetone, where thesecond compound may be alpha-methylstyrene and the substance having aboiling point lower than that of the second compound may comprise one ormore selected from acetone, cumene and water, without being limitedthereto. Furthermore, the substance having a boiling point higher thanthat of the first compound may comprise one or more selected from thegroup consisting of cumene, phenol, and methylphenyl ketone, but is notlimited thereto. In one embodiment, when the boiling point of the secondcompound is higher than that of the first compound, the first top flow(F_(top1)) may be a flow that a concentration of the first compound isrelatively higher than that of the second compound, and the first bottomflow (F_(btm1)) may be a flow that a concentration of the first compoundis relatively lower than that of the second compound.

In the distillation device of the present application, as describedabove, the second compound having a relatively high boiling point, amongthe first and second compounds being capable of forming the azeotrope,is introduced into the supply port located below the first compoundhaving a relatively low boiling point, and thus the first compound canbe previously separated from the top of the first distillation column(100) and the content of the first compound in the flow discharged fromthe bottom of the first distillation column (100) can be minimized Inone example, the content of the first compound in the first bottom flow(F_(btm1)) may be 0.005 to 0.25 parts by weight, for example, 0.01 to0.03 parts by weight, relative to 100 parts by weight of the totalcomponents contained in the first bottom flow (Fb_(tm1)). By controllingthe content of the first compound in the first bottom flow (F_(btm1))within the above range, the content of the first compound separated inthe second distillation column (200) and the third distillation column(300), which are described below, can be minimized, and as the movingroute of the first compound is minimized, the second compound can beseparated in high purity and the energy saving effect can be maximized

In one example, when the content of the first compound in the firstbottom flow (F_(btm1)) of the first distillation column (100) iscontrolled within the above range, the content of the first compound inthe first top flow (F_(top1)) of the first distillation column (100) maybe 0.01 to 2.0 parts by weight, for example, 0.1 to 0.5 parts by weight,relative to 100 parts by weight of the total components contained in thefirst top flow (F_(top1)).

In the unique distillation device of the present application in which aflow (F₁) of the feedstock containing the above mentioned first compoundflows into the first supply port (101) and a flow (F₂) of the feedstockcontaining the second compound being capable of forming an azeotropewith the first compound flows into the second supply port (102) locatedbelow the first supply port (101), another embodiment of the presentapplication provides design conditions of the distillation deviceoptimized in the above distillation device. In one example, thetemperature of the feedstock (F₂) comprising the second compoundintroduced into the second supply port (102) may be from 20 to 180° C.,for example from 23 to 25° C., or from 168 to 172° C. In addition, theflow rate of the feedstock (F₂) containing the second compoundintroduced into the second supply port (102) may be 300 to 1200 kg/hr,for example, 400 to 600 kg/hr, or 900 to 1100 kg/hr.

As in FIG. 1, the distillation device of the present application mayfurther comprise a second distillation unit (20) and a thirddistillation unit (30) in addition to the above mentioned firstdistillation unit (10).

In one embodiment, the distillation device may further comprise thesecond distillation unit (20) and the third distillation unit (30),where the second distillation unit (20) may comprise a second condenser(210), a second reboiler (220) and a second distillation column (200)and the third distillation unit (30) may comprise a third condenser(310), a third reboiler (320) and a third distillation column (300).

A portion of the first bottom flow (F_(btm1)) discharged from the bottomof the first distillation column (100) may flow into the seconddistillation column (200). In addition, the flow introduced into thesecond distillation column (200) may be divided into a second top flow(F_(top2)) discharged from the top region of the second distillationcolumn (200) and a second bottom flow (F_(btm2)) discharged from thebottom region of the second distillation column (200), respectively, anddischarged.

The second top flow (F_(top2)) comprises a relatively low boiling pointcomponent among the components contained in the first bottom flow(F_(btm1)) introduced into the second distillation column (200), and inone example, it may comprise one or more selected from hydroxyacetone,alpha-methylstyrene, phenol and 2-methylbenzofuran, but is not limitedthereto. In addition, the second bottom flow (F_(btm2)) comprises arelatively high boiling point component among the components containedin the first bottom flow (F_(btm1)) introduced into the seconddistillation column (200), and in one example, it may comprisemethylphenyl ketone, dicumyl peroxide, and p-cumylphenol, but is notlimited thereto.

The second top flow (F_(top2)) discharged from the second top region mayflow into the third distillation column (300). In addition, the flowintroduced into the third distillation column (300) can be divided intoa third top flow (F_(top3)) discharged from the top region of the thirddistillation column (300) and a third bottom flow discharged from thebottom region of the third distillation column (300), respectively, anddischarged. The third top flow (F_(top3)) comprises a relatively lowboiling point component among the components contained in the second topflow (F_(top2)) introduced into the third distillation column (300), andin one example, it may comprise one or more selected from the groupconsisting of hydroxyacetone, alpha-methylstyrene and2-methylbenzofuran, but is not limited thereto. In the distillationdevice of the present application, as described above, by controllingthe content of the first compound in the first bottom flow (F_(btm1))within a specific range, the content of the first compound separatedfrom the second distillation column (200) and the third distillationcolumn (300) can be minimized. In one example, the content of the firstcompound, e.g., hydroxyacetone, in the third top flow (F_(top3)) may becontrolled to be included in a very low amount, and for example, it maybe 0.01 to 5.0 parts by weight, relative to 100 parts by weight of thetotal components contained in the third top flow (F_(top3)), but is notlimited thereto.

The third bottom flow comprises a relatively high boiling pointcomponent among the components contained in the second top flow(F_(top2)) introduced into the third distillation column (300), and inone example, it may comprise one or more selected from the groupconsisting of phenol, and water, but is not limited thereto. In oneembodiment, the third bottom flow may be a flow of pure phenol.

Hereinafter, the process of separating phenol and hydroxyacetone usingthe distillation device according to one embodiment of the presentapplication will be described in more detail.

In one example, a feedstock (F₁) containing hydroxyacetone and phenolflows into the first supply port (101) of the first distillation column(100), and a feedstock (F₂) containing alpha-methylstyrene being capableof forming an azeotrope with the hydroxyacetone flows into the secondsupply port (102) located below the first supply port (101) of the firstdistillation column (100).

In this case, the flow that pure acetone is rich, which is a relativelylow boiling point component among the components contained in thefeedstock (F₁) introduced into the first supply port (101), may flow outof the top region of the first distillation column (100) as the firsttop flow (F_(top1)), and the flow that phenol is rich, which is arelatively high boiling point component, may flow out of the bottomregion of the first distillation column (100) as the first bottom flow(F_(btm1)). The first top flow (F_(top1)) discharged from the top regionof the first distillation column (100) may pass through the firstcondenser (110) to reflux to the top region of the first distillationcolumn (100), and the remaining portion may be stored as a product. Theproduct may be pure acetone in high purity. The first top flow(F_(top1)) may contain some cumene, alpha-methylstyrene andhydroxyacetone in addition to acetone, and as described above, thecontent of hydroxyacetone in the first top flow (F_(top1)) may be 0.01to 2.0 parts by weight relative to 100 parts by weight of the totalcomponents contained in the first top flow (F_(top1)).

Moreover, a portion of the first bottom flow (F_(btm1)) discharged fromthe bottom region of the first distillation column (100) may passthrough the first reboiler (120) for some to be refluxed to the bottomregion of the first distillation column (100) and for the remainingportion to flow into the second distillation column (200). In addition,the flow that phenol is rich, which is a relatively low boiling pointcomponent among the components contained in the feedstock flowintroduced into the second distillation column (200), may flow out ofthe top region of the second distillation column (200) as the second topflow (F_(top2)), and the flow that methylphenyl ketone with a relativelyhigh boiling point is rich, may flow out of the bottom of the seconddistillation column (200) as the second bottom flow (F_(btm2)). Thedischarged second top flow (F_(top2)) may flow into the storage tank viathe second condenser (210) for a portion of the flow discharged from thestorage tank to be refluxed to the top region of the second distillationcolumn (200) and for the remaining portion to flow into the thirddistillation column (300). In addition, the high boiling point flowhaving a relatively high boiling point among the components contained inthe flow introduced into the second distillation column (200) may flowout of the bottom of the second distillation column (200) as the secondbottom flow (F_(btm2)) for a portion of the second bottom flow(F_(btm2)) to be refluxed to the bottom region of the seconddistillation column (200) via the second reboiler (220) and for theremaining portion to be stored as a product. The product may bemethylphenyl ketone in high purity.

The second top flow (F_(top2)) discharged from the top region of thesecond distillation column (200) may flow into the third distillationcolumn (300). The flow that alpha-methylstyrene is rich, which is arelatively low boiling point component among the components contained inthe second top flow (F_(top2)) introduced into the third distillationcolumn (300), may flow out of the top region of the third distillationcolumn (300) as the third top flow (F_(top3)), the third top flow(F_(top3)) discharged from the top region of the third distillationcolumn (300) may pass through the third condenser (310) to be refluxedto the top region of the third distillation column (300), and theremaining portion can be stored as a product. The product may bealpha-methylstyrene in high purity. In this case, the content ofhydroxyacetone in the third top flow (F_(top3)) may be adjusted to avery small range, and for example, the content of hydroxyacetone may be0.01 to 5.0 parts by weight, relative to 100 parts by weight of thecomponents contained in the third top flow (F_(top3)). In addition, thehigh boiling point flow having a relatively high boiling point among thecomponents contained in the flow introduced into the third distillationcolumn (300) may flow out of the bottom region of the third distillationcolumn (300) as the third bottom flow (F_(btm3)) for a portion of thethird bottom flow (F_(btm3)) to be refluxed to the bottom region of thethird distillation column (300) via the third reboiler (320) and for theremaining portion to be stored as a product. The product may be phenolin high purity.

The term “low boiling point flow” herein means a flow in which arelatively low boiling point component among the feedstock flowcomprising low boiling point and high boiling point components is rich,and the low boiling point flow means, for example, a flow dischargedfrom the top region of the first distillation column (100), the seconddistillation column (200) and the third distillation column (300). Also,the “high boiling point flow” means a flow in which a relatively highboiling point component among the feedstock flow comprising low boilingpoint and high boiling point components is rich, and the high boilingpoint flow means, for example, a flow that a relatively high boilingpoint component is rich, discharged from the bottom region of the firstdistillation column (100), the second distillation column (200) and thethird distillation column (300). The term “rich flow” in the above meansthe flow having each content of low boiling point components containedin the flow discharged from the top region of the first distillationcolumn (100), the second distillation column (200) and the thirddistillation column (300) and high boiling point components contained inthe flow discharged from the bottom region of the first distillationcolumn (100), the second distillation column (200) and the thirddistillation column (300), higher than each content of low boiling pointcomponents and high boiling point components contained in the feedstocksintroduced into the first distillation column (100), the seconddistillation column (200) and the third distillation column (300),respectively. For example, it may means a flow that each contentrepresented by the low boiling point component contained in the firsttop flow (F_(top1)) of the first distillation column (100), the lowboiling point component contained in the second top flow (F_(top2)) ofthe second distillation column (200) and the low boiling point componentcontained in the third top flow (F_(top3)) of the third distillationcolumn (300) is at least 50% by weight, at least 80% by weight, at least90% by weight, at least 95% by weight, or at least 99% by weight or meana flow that each content represented by the high boiling point componentcontained in the first bottom flow (F_(btm1)) of the first distillationcolumn (100) and the high boiling point component contained in thesecond bottom flow (F_(btm2)) of the second distillation column (200)and the high boiling point component contained in the third bottom flow(F_(btm3)) of the third distillation column (300) is at least 50% byweight, at least 80% by weight, at least 90% by weight, at least 95% byweight, or at least 99% by weight.

The present application also provides the above distillation method. Anexemplary distillation method of the present application can be carriedout using the above-described distillation device, and accordingly, thecontents overlapping with those described in the above-mentioneddistillation device will be omitted.

The preparation method of the present application comprises a feedstocksupply step and a first distillation step.

In one embodiment, the feedstock supply step comprises i) introducing afeedstock (F₁) comprising the first compound into the first supply port(101) of the first distillation column (100), and ii) introducing afeedstock (F₂) comprising the second compound forming an azeotrope withthe first compound 1 into the second supply port (102) located below thefirst supply port (101) and located at 40 to 100% of the number oftheoretical stages calculated on the basis of the top. In addition, thefirst distillation step comprises iii) discharging the feedstockcomprising the first and second compounds introduced into the firstsupply port and the second supply port (102) as the first top flow(F_(top1)) discharged from the top region of the first distillationcolumn (100) and the first bottom flow (F_(btm1)) discharged from thebottom region of the first distillation column (100).

Since the steps i) and ii) of the feedstock supply step and the stepiii) of the first distillation step are each independently organicallybonded, each boundary is not clearly divided according to the order oftime, and thus the respective steps of i) to iii) may be performedsequentially or each independently at the same time.

In one embodiment, the first top flow (F_(top1)) comprises the firstcompound, the second compound and a substance having a boiling pointlower than that of the second compound, and the first bottom flow(F_(btm1)) comprises the first compound and a substance a boiling pointhigher than that of the first compound, and detailed descriptionsthereof will be omitted since they are the same as those described inthe above-mentioned distillation device.

In addition, the content of the first compound in the first bottom flow(F_(btm1)) may be 0.005 to 0.25 parts by weight, for example, 0.01 to0.03 parts by weight, relative to 100 parts by weight of the totalcomponents contained in the first bottom flow (F_(btm1)). By controllingthe content of the first compound in the first bottom flow (F_(btm1))within the above range, the content of the first compound separated inthe second distillation column (200) and the third distillation column(300), which are described below, can be minimized, and as the movingroute of the first compound is minimized, the second compound can beseparated in high purity and the energy saving effect can be maximized

In one example, when the content of the first compound in the firstbottom flow (F_(btm1)) of the first distillation column (100) isadjusted within the above range, the first top flow (F_(top1)) of thefirst distillation column (100) may be 0.01 to 2.0 parts by weight, forexample, 0.1 to 0.5 parts by weight, relative to 100 parts by weight ofthe total components contained in the first top flow (F_(top1)).

In the distillation method of the present application, the temperatureof the first top flow (F_(top1)) discharged from the top region of thefirst distillation column (100) may be 89° C. to 107° C., for example,90° C. to 100° C. In addition, the temperature of the first bottom flow(F_(btm1)) discharged from the bottom of the first distillation column(100) may be 197° C. to 219° C., for example, 190° C. to 210° C.

In addition, in this case, the pressure of the top region of the firstdistillation column (100) may be 0.01 to 1.0 kgf/cm²g, for example, 0.1to 0.5 kgf/cm²g. Also, the pressure of the bottom region of the firstdistillation column (100) may be 0.5 to 1.5 kgf/cm²g, for example, 0.5to 1.0 kgf/cm²g.

In one example, the first compound may be hydroxyacetone, where thesecond compound may be alpha-methylstyrene and the substance having aboiling point lower than that of the second compound may comprise one ormore selected from the group consisting of acetone, cumene and water,without being limited thereto. In addition, the substance having aboiling point higher than that of the first compound may comprise one ormore selected from the group consisting of cumene, phenol, andmethylphenyl ketone, but is not limited thereto.

In one example, the temperature of the feedstock (F₂) comprising thesecond compound introduced into the second supply port (102) may be 20to 180° C., for example, 23 to 25° C., or 168 to 172° C. In addition,the flow rate of the feedstock (F₂) comprising the second compoundintroduced into the second supply port (102) may be 300 to 1200 kg/hr,for example, 400 to 600 kg/hr, or 900 to 1100 kg/hr.

Advantageous Effects

According to the distillation device of the present application, byintroducing the second compound having a relatively high boiling point,among the first and second compounds being capable of forming theazeotrope, into the supply port located below the first compound havinga relatively low boiling point, the first compound can be previouslyseparated from the top of the first distillation column and the contentof the first compound in the flow discharged from the bottom of thefirst distillation column can be minimized, and thus as the moving routeof the first compound is minimized, the second compound can be separatedin high purity.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustratively showing a distillation deviceaccording to one embodiment of the present application.

FIGS. 2 to 5 are diagrams schematically showing distillation devicesused in Examples 1 to 4 of the present application.

FIG. 6 is a diagram illustratively showing a typical separationapparatus used in Comparative Example.

10: first distillation unit

100: first distillation column 101: first supply port

102: second supply port 110: first condenser

120: first reboiler 20: second distillation unit

200: second distillation column 210: second condenser

220: second reboiler 30: third distillation unit

300: third distillation column 310: third condenser

320: third reboiler F₁: feedstock containing the first compound

F₂: feedstock containing the second compound forming an azeotrope withthe first compound

F_(top1): first top flow F_(btm1): first bottom flow

F_(top2): second top flow F_(btm2): second bottom flow

F_(top3): third top flow F_(btm3): third bottom flow

MODE FOR INVENTION

Hereinafter, the present invention will be described in more detailthrough Examples complying with the present invention and ComparativeExample uncomplying with the present invention, but the scope of thepresent invention is not limited by the proposed examples.

Example 1

Phenol and hydroxyacetone were separated using the distillation deviceof FIG. 2.

Specifically, a feedstock containing 29% by weight of acetone, 9% byweight of cumene, 3% by weight of alpha-methylstyrene, 0.2% by weight ofhydroxyacetone, 46% by weight of phenol and 3% by weight of a highboiling point component was introduced into the first supply portlocated at the 20th stage of the first distillation column having anumber of theoretical stages of 65 at a temperature of 106° C. and aflow rate of 85,000 kg/hr. Furthermore, in addition to this, a feedstockcontaining 99.8% by weight of alpha-methylstyrene was introduced intothe second supply port located at the 65th stage of the firstdistillation column at a temperature of 170.6° C. and a flow rate of 500kg/hr.

The first top flow discharged from the top region of the firstdistillation column passed through the first condenser and a portion wasrefluxed to the top region of the first distillation column. Theremaining portion of the first top flow was separated and stored as aproduct comprising 56% by weight of acetone, 17% by weight of cumene, 6%by weight of alpha-methylstyrene and 0.3% by weight of hydroxyacetone,and the first bottom flow discharged from the bottom region of the firstdistillation column passed through the first reboiler, and a portion wasrefluxed to the bottom region of the first distillation column and theremaining portion was introduced into the second distillation column Inthis case, the operating pressure of the first distillation column topregion was adjusted to 0.2 kgf/cm²g, the operating temperature wasadjusted to 94.1° C., the operating pressure of the first distillationcolumn bottom region was adjusted to 0.716 kgf/cm²g, and the operatingtemperature was adjusted to be 203.1° C.

Furthermore, the second top flow discharged from the top region of thesecond distillation column passed through the second condenser, and aportion was refluxed to the top region of the second distillation columnand the remaining portion was introduced into the third distillationcolumn. A portion of the second bottom flow discharged from the bottomregion of the second distillation column was refluxed to the bottomregion of the second distillation column through the second reboiler andthe remaining portion was separated as a product comprising 21% byweight of methylphenyl ketone and 20% by weight of p-cumylphenol. Inthis case, the operating pressure of the top region of the seconddistillation column was adjusted to −0.666 kgf/cm²g, the operatingtemperature was adjusted to be 147° C., the operating pressure of thebottom region of the second distillation column was −0.291 kgf/cm²g andthe operating temperature was adjusted to be 213° C.

In addition, the third top flow discharged from the top region of thethird distillation column passed through the third condenser, and aportion was refluxed to the top region of the third distillation columnand the remaining portion was stored as a product comprising 0.11% byweight of hydroxyacetone and 68% by weight of alpha-methylstyrene. Aportion of the third bottom flow discharged from the bottom region ofthe third distillation column was refluxed to the bottom region of thethird distillation column via the third reboiler and the remainingportion was separated as a product containing pure phenol. In this case,the operating pressure of the top region of the third distillationcolumn was adjusted to 0.03 kgf/cm²g, the operating temperature wasadjusted to be 85° C., the operating pressure of the bottom region ofthe third distillation column was adjusted to 1.32 kgf/cm²g, and theoperating temperature was adjusted to be 214° C.

In the case of separating phenol and hydroxyacetone using thedistillation device of Example 1, the content of hydroxyacetone in thefirst bottom flow, the used amount of energy in the first and secondreboilers, the amount of reduction, the rate of reduction and the purityof the phenol product were shown in Table 1 below.

EXAMPLES 2 TO 10

Phenol and hydroxyacetone were separated by the same method as Example1, except that the operating conditions of the first distillation columnand the second distillation column were changed as in Table 1 below.

In the case of separating phenol and hydroxyacetone using thedistillation devices of Examples 2 to 10, the content of hydroxyacetonein the first bottom flow, the used amount of energy in the reboilers,the amount of reduction, the rate of reduction and the purity of thephenol products were shown in Table 1 below.

COMPARATIVE EXAMPLE

Phenol and hydroxyacetone were separated using the distillation deviceof FIG. 2.

Specifically, a feedstock comprising 29% by weight of acetone, 9% byweight of cumene, 3% by weight of alpha-methylstyrene, 0.2% by weight ofhydroxyacetone, 46% by weight of phenol and 3% by weight of a highboiling point component was introduced into the first supply portlocated at the 20th stage of the first distillation column having anumber of theoretical stages of 65.

The first top flow discharged from the top region of the firstdistillation column passed through the first condenser and a portion wasrefluxed to the top region of the first distillation column. Theremaining portion of the first top flow was separated and stored as aproduct comprising 56% by weight of acetone, 17% by weight of cumene, 5%by weight of alpha-methylstyrene and 0.3% by weight of hydroxyacetone,and a portion of the first bottom flow discharged from the bottom regionof the first distillation column was refluxed to the bottom region ofthe first distillation column via the first reboiler and the remainingportion flowed into the second distillation column. In this case, theoperating pressure of the first distillation column top region wasadjusted to 0.2 kgf/cm²g, the operating temperature was adjusted to93.4° C., the operating pressure of the first distillation column bottomregion was adjusted to 0.716 kgf/cm²g, and the operating temperature wasadjusted to be 203.1° C.

Furthermore, the second top flow discharged from the top region of thesecond distillation column passed through the second condenser, and aportion was refluxed to the top region of the second distillation columnand the remaining portion was introduced into the third distillationcolumn. A portion of the second bottom flow discharged from the bottomregion of the second distillation column was refluxed to the bottomregion of the second distillation column through the second reboiler andthe remaining portion was separated as a product. In this case, theoperating pressure of the top region of the second distillation columnwas adjusted to −0.666 kgf/cm²g, the operating temperature was adjustedto be 147° C., the operating pressure of the bottom region of the seconddistillation column was −0.291 kgf/cm²g and the operating temperaturewas adjusted to be 213° C.

In addition, the third top flow discharged from the top region of thethird distillation column passed through the third condenser, and aportion was refluxed to the top region of the third distillation columnand the remaining portion was stored as a product comprising 1.08% byweight of hydroxyacetone. A portion of the third bottom flow dischargedfrom the bottom region of the third distillation column was refluxed tothe bottom region of the third distillation column via the thirdreboiler and the remaining portion was separated as a product containingpure phenol. In this case, the operating pressure of the top region ofthe third distillation column was adjusted to 0.03 kgf/cm²g, theoperating temperature was adjusted to be 83° C., the operating pressureof the bottom region of the third distillation column was adjusted to1.32 kgf/cm²g, and the operating temperature was adjusted to be 214° C.

In the case of separating phenol and hydroxyacetone using thedistillation device of Comparative Example, the content ofhydroxyacetone in the first bottom flow, the used amount of energy inthe reboilers, the amount of reduction, the rate of reduction and thepurity of the phenol product were shown in Table 1 below.

TABLE 1 Heat duty of reboilers Total used Content amount of HA in ofenergy Input the first in the Purity Input number of Input bottom firstand Amount of temperature theoretical amount flow second of Rate ofphenol of AMS stages of of AMS ( % by reboilers reduction reduction (%by (° C.) AMS (kg/hr) weight) (Gcal/hr) (Gcal/hr) (%) weight) Example 1170.6 Stage 65 500 0.131 16.07 0.72 4.31 99.99 (bottom) Example 2 170.6Stage 65 1000 0.051 16.20 0.60 3.56 99.99 (bottom) Example 3 24.0 Stage65 500 0.131 16.11 0.69 4.12 99.99 (bottom) Example 4 24.0 Stage 65 10000.051 16.27 0.53 3.16 99.99 (bottom) Example 5 170.6 Stage 61 500 0.15916.23 0.57 3.40 99.99 Example 6 170.6 Stage 61 1000 0.094 16.06 0.744.42 99.99 Example 7 170.6 Stage 51 500 0.186 16.42 0.38 2.28 99.99Example 8 170.6 Stage 51 1000 0.138 16.28 0.52 3.10 99.99 Example 9170.6 Stage 36 500 0.203 16.52 0.28 1.65 99.99 Example 10 170.6 Stage 361000 0.164 16.41 0.39 2.33 99.99 Comparative — — — 0.258 16.80 — — —Example

1. A distillation device comprising a first distillation unit comprisinga first distillation column having a first supply port and a secondsupply port located below the first supply port, a first condenser and afirst reboiler, wherein a feedstock comprising a first compound flowsinto said first supply port and a feedstock comprising a second compoundforming an azeotrope with said first compound flows into said secondsupply port, wherein the feedstocks comprising said first and secondcompound introduced into said first and second supply ports are dividedinto a first top flow discharged from the top region of said firstdistillation column and a first bottom flow discharged from the bottomregion of said first distillation column, respectively, and discharged,wherein said first top flow flows into said first condenser and some orall of the first top flow passing through said first condenser isrefluxed to the top region of said first distillation column, wherein aportion of said first bottom flow flows into said first reboiler and aportion of said first bottom flow passing through said first reboiler isrefluxed to the bottom region of said first distillation column, whereinsaid first top flow comprises said first compound, said second compoundand a substance having a boiling point lower than that of said secondcompound, and said first bottom flow comprises said first compound and asubstance having a boiling point higher than that of said firstcompound, and wherein the content of said first compound in said firstbottom flow is 0.005 to 0.25 parts by weight relative to 100 parts byweight of the total components contained in said first bottom flow. 2.The distillation device according to claim 1, wherein the content of thefirst compound in the first top flow is 0.01 to 2.0 parts by weightrelative to 100 parts by weight of the total components contained insaid first top flow.
 3. The distillation device according to claim 1,wherein the first compound is hydroxyacetone.
 4. The distillation deviceaccording to claim 3, wherein the second compound isalpha-methylstyrene.
 5. The distillation device according to claim 3,wherein the substance having a boiling point lower than that of thesecond compound comprises one or more selected from the group consistingof acetone, cumene, and water.
 6. The distillation device according toclaim 3, wherein the substance having a boiling point higher than thatof the first compound comprises one or more selected from the groupconsisting of cumene, phenol and methylphenyl ketone.
 7. Thedistillation device according to claim 1, wherein the first supply portis located at 1 to 40% of the number of theoretical stages calculated onthe basis of the top.
 8. The distillation device according to claim 1,wherein the second supply port is located at 40 to 100% of the number oftheoretical stages calculated on the basis of the top.
 9. Thedistillation device according to claim 1, wherein a temperature of thefeedstock containing the second compound introduced into the secondsupply port is 20 to 180° C.
 10. The distillation device according toclaim 1, wherein a flow rate of the feedstock containing the secondcompound introduced into the second supply port is 300 to 1200 kg/hr.11. The distillation device according to claim 1, further comprising asecond distillation unit comprising a second condenser, a secondreboiler and a second distillation column; and a third distillation unitcomprising a third condenser, a third reboiler and a third distillationcolumn, wherein a portion of the first bottom flow discharged from thebottom region of the first distillation column flows into said seconddistillation column and the flow introduced into said seconddistillation column is divided into a second top flow discharged fromthe top region of said second distillation column and a second bottomflow discharged from the bottom region of said second distillationcolumn, respectively, and discharged, wherein said second top flow flowsinto said third distillation column and the flow introduced into saidthird distillation column is divided into a third top flow dischargedfrom the top region of said third distillation column and a third bottomflow discharged from the bottom region of said third distillationcolumn, respectively, and discharged, and wherein the content of thefirst compound in said third top flow is 0.01 to 5.0 parts by weightrelative to 100 parts by weight of the total components contained insaid third top flow.
 12. The distillation device according to claim 11,wherein the third bottom flow is a flow of pure phenol.
 13. Adistillation method comprising a feedstock supply step of introducing afeedstock comprising a first compound into a first supply port of afirst distillation column and introducing a feedstock comprising asecond compound forming an azeotrope with said first compound into asecond supply port located below said first supply port and located at40 to 100% of the number of theoretical stages calculated on the basisof the top; and a first distillation step of discharging feedstockscomprising said first and second compounds introduced into said firstand second supply ports as a first top flow discharged from the topregion of said first distillation column and a first bottom flowdischarged from the bottom region of said first distillation column,respectively, wherein said first top flow comprises said first compound,said second compound and a substance having a boiling point lower thanthat of said second compound, and said first bottom flow comprises saidfirst compound and a substance having a boiling point higher than thatof said first compound, and wherein the content of said first compoundin said first bottom flow is 0.005 to 0.25 parts by weight relative to100 parts by weight of the total components contained in said firstbottom flow.
 14. The distillation method according to claim 13, whereinthe content of the first compound in the first top flow is 0.01 to 2.0parts by weight relative to 100 parts by weight of the total componentscontained in said first top flow.
 15. The distillation method accordingto claim 13, comprising adjusting a temperature of the top region of thefirst distillation column to 89 to 107° C.
 16. The distillation methodaccording to claim 13, comprising adjusting a temperature of the bottomregion of the first distillation column to 197 to 219° C.
 17. Thedistillation method according to claim 13, comprising adjusting apressure of the top region of the first distillation column to 0.01 to10. kgf/cm²g.
 18. The distillation method according to claim 13,comprising adjusting a pressure of the bottom region of the firstdistillation column to 0.5 to 1.5 kgf/cm²g.
 19. The distillation processaccording to claim 13, wherein the first compound is hydroxyacetone andthe second compound is alpha-methylstyrene.
 20. The method according toclaim 19, wherein the substance having a boiling point lower than thatof the second compound comprises one or more selected from the groupconsisting of acetone, cumene and water, and the substance having aboiling point higher than that of the first compound comprises one ormore selected from the group consisting of cumene, phenol andmethylphenyl ketone.
 21. The distillation method according to claim 13,comprising adjusting a temperature of the feedstock containing thesecond compound introduced into the second supply port to 20 to 180° C.22. The distillation method according to claim 13, comprising adjustinga flow rate of the feedstock containing the second compound introducedinto the second supply port to 300 to 1200 kg/hr.